dhis2-users team mailing list archive

[Calle Hedberg <calle.hedberg@xxxxxxxxx>]

Robin,

Unlikely that the "number of tracked entities" operator will work for
programs defined as single events without registration, because that
type of program does not have ANY entities.

A relatively simple work-around is to define one extra data element in
your event - maybe called just "Event" - with a default value of 1.
Adding those up will give you the number of events.

We've been using Single Events for storing a range of survey data -
every survey or sub-survey (questionnaire) is defined as a program.
With the aggregation query builder (a) running against the raw event
data value table and not the analytics event tables; and (b) inability
to use a weighting factor on each case before aggregation, we
(HISP-SA) have  designed an app that filters a range of cases based on
whatever criteria is relevant, multiplies the base value with a
weighting factor if required, and then aggregates the (weighted) base
value up to district or national level and inserts the aggregated
records into the datavalues table.

Since many indicators will require the number of cases as the
denominator, it makes sense to have one "Event" or "Survey_Respondent"
data element with number = 1 for all cases. So when calculating e.g.
the indicator "Households with safe water rate", we can generate both
the (weighted) total number of households in the survey and then
filter all the households for specific criteria based on one or more
"Household source of drinking water" and then aggregate that up
(weighted) to form the numerator data.

The app is still a bit crude, but I expect we will be able to polish
it up and publish it to the library shortly.

Regards
calle

On 21/01/2015, Robin Martens <martens@xxxxxxx> wrote:
> Hi all,
>
> Is it possible in the Aggregation Query Builder to use the "Number of
> tracked entities" operator to calculate a number of events, especially when
> it concerns Single events without registration?
>
> I tried it and although it finds the events based on the conditions, it
> always returns 0 as a value.
>
> Regards,
>
> Robin
>


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Calle Hedberg

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